The invention relates generally to surgical stapling appliances and more particularly to an improved apparatus and method for the anastomotic surgical stapling of luminal organs, such as vascular lumens.
Various instruments are known in the prior art for end-to-end and end-to-side anastomotic surgical stapling together of parts of the alimentary canal (i.e., esophagus, stomach, colon, etc.). These instruments employ staple cartridges, generally in the shape of a hollow cylinder, of different sizes to accommodate tubular organs of varying diameters. End-to-end and end-to-side anastomoses are achieved by means of at least one ring of surgical staples.
The traditional technique for surgical stapling anastomosis is to position the stapling cartridge within the tubular organ to be stapled. The cut end of the tubular organ is inverted (i.e. folded inwardly) over the annular end of the staple cartridge creating an inverting anastomosis upon stapling. An essential requirement of the inverting anastomotic technique is the incorporation of knives within the staple cartridge to trim excess tissue from the anastomotic connection.
The prior art anastomotic stapling instruments form generally circular anastomotic connections, and have been largely limited to alimentary organs. With respect to end-to-side vascular anastomosis, circular connections, rather than an elliptical connections, are sometimes disadvantageous as they are less physiologic or natural. This unnatural connection may create turbulence in the blood flow as it courses through the anastomosis, damaging the intima (i.e. inner wall) of the blood vessel and predisposing it to forming blood clots.
In the present state of the art, end-to-end and end-to-side anastomosis between blood vessels have typically been accomplished by hand-sewn suturing techniques. These techniques are time consuming, not as reliable as stapling, and subject to greater human error than stapling. Current stapling instruments used for alimentary canal are not suitable, however, for vascular anastomosis due to their large sizes and inability to provide non-circular and low turbulence anastomoses. A typical prior art instrument has a circumference of approximately 8 cm (3 in), far too thick to accommodate coronary arteries and veins, which have circumferences ranging from 0.50 to 1.0 cm and from 1.5 to 2.5 cm, respectively.
An additional drawback of prior stapling instruments is the inability to provide an everted (i.e. folded outwardly) anastomosis. An inverted vascular anastomosis would expose the cut ends of the blood vessels to the vessel lumen and could lead to the formation of blood clots. For this reason, hand-sewn everted anastomoses for vascular connections are preferable, despite time and reliability drawbacks.
Accordingly, it is a general object of the present invention to provide an improved instrument and method for vascular anastomosis.
It is also an object of the present invention to provide a surgical anastomosis apparatus small enough to accommodate vascular lumens.
Another object of the present invention is to provide a surgical anastomosis apparatus for everted anastomosis.
Another object of the present invention is to provide a method for surgical stapling that does not require the removal of excess tissue from the anastomotical connection.
Still another object of the present invention is to provide an instrument and method for vascular anastomosis that is less time-consuming and more reliable than the prior art.
The present invention provides a novel instrument and method for vascular anastomoses which overcomes the drawbacks of prior art designs and achieves the aforesaid advantages.
Very generally, the surgical stapling instrument of the present invention is for stapling a tubular tissue structure having at least one distal end to a luminal structure, such as a vascular lumen or another tubular tissue structure. The instrument comprises a rod having a circumference sufficient to pass within the tubular tissue structure, an anvil mounted on the rod, and a generally tubular staple cartridge for containing a plurality of staples. The anvil has an array of staple deforming means thereon and is of a size sufficient to pass through a surgically formed opening in and to be accommodated within the luminal structure. The inner passage of the staple cartridge is sufficient to axially accommodate the tubular tissue structure between the rod and the inner surface of the staple cartridge, and sufficient to allow the staple cartridge to be moved axially along the rod. The staple delivery end of the staple cartridge is positioned toward the staple deforming means of the anvil and has an outer dimension small enough so that the tubular tissue structure can be everted thereover. A clamping mechanism secures the everted portion of the tubular tissue structure and the luminal structure adjacent to the surgically formed opening between the staple cartridge and the anvil. A plurality of staples may then be ejected to pass through the everted portion of the tubular tissue structure and the luminal structure to engage the staple deforming means to deform the staples and create a bond between the tubular tissue structure and the luminal structure.
In another aspect of the present invention, an end-to-side surgical anastomosis apparatus is provided for stapling an end of a tubular tissue structure to a side of a luminal structure. The anastomosis apparatus includes an elongated housing defining a central bore extending longitudinally therethrough and terminating at a bore opening at a distal end of the housing. The central bore includes a transverse cross-sectional dimension sufficiently sized and configured for receipt of the tissue structure therein in a manner positioning the end of the tissue structure through the bore opening. The elongated housing further includes an eversion support surface extending circumferentially about the bore opening adjacent the distal end. This surface is configured to retain and support an everted end of the received tissue structure which extends through the bore opening to face an intimal surface of the tissue structure in an outward direction. The anastomosis apparatus further includes an anvil having a fastener engaging surface, and a compression device having a shoulder portion formed for selectively compressing the everted end of the tissue structure and a surface of the luminal structure together against the fastener engaging surface. The compression device is further formed to deform the fasteners into contact with the everted end of the tubular tissue structure and the luminal structure to create an anastomotic bond between the tubular tissue structure and the luminal structure.
At least one driver pin is preferably provided moveable relative to the compression device for ejecting the plurality of fasteners through the everted end of the tubular tissue structure and the luminal structure to engage the fastener engaging surface. This engagement deforms the fastener and creates a bond between the tubular tissue structure and the luminal structure.
In still another aspect of the present invention, a method of end-to-side surgical anastomosis is provided between a tubular tissue structure, having at least one end, and a luminal structure, such as a vascular lumen or another tubular tissue structure. The method includes the steps of A) inserting the tubular tissue structure in a central bore of an anastomosis apparatus, and B) everting an end of the tubular tissue structure over and against an eversion support surface of the anastomosis device and at a distal end of the central bore to an everted condition positioning an intimal surface of the everted end in a direction facing outwardly. The next steps of the present invention include C) positioning the everted end of the tubular tissue structure and a surface of the luminal structure between an anvil and an opposed shoulder of a compression device of the anastomosis apparatus, and D) contacting the intimal surface of the everted end with a surface of the luminal structure adjacent a surgically formed opening therein. Finally, the last step of the method of end-to-side surgical anastomosis of the present invention includes E) applying a plurality of fasteners to the everted end of the tubular tissue structure and the surface of the luminal structure to contact the anvil and deform the fasteners to form an anastomotic bond therebetween.